Abstrakt: |
Body composition is quite different in the fetus and newborn, as compared to that of older infants, children and adults, but changes rapidly over the first weeks to months of life with a loss of extracellular fluid and total body water and a gain of intracellular fluid. At all ages, the volume, distribution, composition, and tonicity of the body fluids are very carefully regulated as are the pH and major buffer systems. An understanding of the normal anatomy of the body fluids and of the controlling homeostatic feedback mechanisms is vital to the understanding of fluid electrolyte and acid-base derangements. |